"We cannot accept any part of this initiative," General Selim Idriss told reporters in Istanbul.

He preceded that by saying: "We in the Free Syrian Army are unconcerned by the implementation of any part of the initiative... I and my brothers in arms will continue to fight until the regime falls."

Idriss spoke shortly after U.S. Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov announced after three days of talks an agreement that would see Syria's vast chemical arsenal removed and destroyed by mid-2014.

"Are we Syrians supposed to wait until mid-2014, to continue being killed every day, and to accept (the deal) just because the chemical arms will be destroyed in 2014," asked Idriss.

"We respect our friends (in the international community), and we hope our friends understand our position... We cannot accept this initiative because it ignores... the massacres of our people."

The Kerry-Lavrov breakthrough came in the wake of U.S. and French threats to strike the regime of President Bashar Assad for allegedly using chemical arms near Damascus on August 21 that killed hundreds.

Damascus has accused the rebels of the attack.

The strike plans were put off after Russia proposed that Damascus hand over its chemical arms to international supervision, to which Assad agreed.

Idriss also accused Russia of plotting with Damascus to find a safe exit for Assad.

"When the regime agreed to hand over the weapons, it recognized its crime. So should the weapons be handed over, without handing over the criminal," he asked.

"I call for Bashar Assad to be dragged to the International Criminal Court today because he is a criminal."